That's right. No light escapes from a black hole horizon because the gravitational red shift stretches the wave length so that it can't get out. Of course the other way to look at it is that time for the wave, in the reference frame of the light wave, is slowed down to 0, in comparison with clocks in our reference frame. The original conception of the black hole was that the escape velocity for a black hole is greater than the speed of light. So there are several ways of thinking of it, depending on what way you want to look at it.

Bill Gill


C is not the speed of light in a vacuum.
C is the universal speed limit.